Beginner Flowers: End the Debate: Deadheading Petunias

My mom and I are involved in a debate about deadheading petunias. She was complaining that hers are looking kindof drab. We started talking about deadheading and she said she always pinches hers all the way back. I told her that mine are looking fabulous because I always just popped the bloom out, leaving the green stem it originated from (sorry don't know correct terminology). Please help us resolve this debate. Who is right? Thanks!!

Leaving the green stem is not deadheading. That's where the seeds are forming. Eventually the little nub at the tip will turn brown, open, and the seeds will come out. Is the debate whether or not deadheading prolongs bloom period (I think it does,) or whether or not you are actually deadheading?

To DEADHEAD a plant is to remove the spent flower AND the seed source/pod. You have to remove the seed source in order to encourage more blooms and to do this, you have to remove the whole flower, not just the spent petals.

Just to make sure there is visual confirmation of the difference between the end of the flower stem which should be pinched, but not the growth tip end of the stem where the new flowers are forming. If you do that, it will definitely cause a lag in blooming BUT can be a way to encourage a leggy plant to make some new branches.

the wave petunias also bloom profusely, but to me all petunias like a hard cutting back when they get lanky,ugly,brown,yellowing,sparse leaves lol. but when they are still bushy and green you should just deadhead.
after a few months you can do what you mom does, and whack them down.
that's what i do, but everyone does things differently lol